A prince-bishop is a bishop who is the civil governor of some secular principality. Thus the principality ruled politically by a prince-bishop could wholly or largely overlap with his diocesan jurisdiction, since some parts of his diocese, even the city of his residence, could be exempt from his civil rule, obtaining the status of free imperial city. If the episcopal see is an archbishopric, the correct term is prince-archbishop; the equivalent in the regular (monastic) clergy is prince-abbot.

In the West, with the decline of imperial power from the 4th century onwards in the face of the barbarian invasions, sometimes Christian bishops of cities took the place of the Roman commander, made secular decisions for the city and led their own troops when necessary. Later relations between a prince-bishop and the burghers were invariably not cordial. As cities demanded charters from emperors, kings, or their prince-bishops and declared themselves independent of the secular territorial magnates, friction intensified between burghers and bishops.

In the Byzantine Empire, the still autocratic Emperors passed general legal measures assigning all bishops certain rights and duties in the secular administration of their dioceses, but that was part of a caesaropapist development putting the Eastern Church in the service of the Empire, with its Ecumenical Patriarch almost reduced to the Emperor's minister of religious affairs. The Russian Empire went even further, abolishing its own patriarchy and placing the church under direct control of the secular government.

The stem duchies of the German kingdom inside the Empire had strong and powerful dukes (originally, war-rulers), always more looking out for their duchy's "national interest" than for the Empire's. In turn the first Ottonian (Saxon) king Henry the Fowler and more so his son, Emperor Otto I, intended to weaken their power by granting loyal bishops Imperial lands and vest them with regalia privileges. Unlike dukes they could not pass hereditary titles and lands to any descendants. Instead the Emperors reserved the implementation of the bishops of their proprietary church for themselves, defying the fact that according to canon law they were part of the transnational Catholic Church. This met with increasing opposition by the Popes, culminating in the fierce Investiture Controversy of 1076. Nevertheless the Emperors continued to grant major territories to the most important (arch)bishops. The immediate territory attached to the episcopal see then became a prince-diocese or bishopric (Fürstbistum).[1] The German term Hochstift was often used to denote the form of secular authority held by bishops ruling a prince-bishopric with Erzstift being used for prince-archbishoprics.

No less than three of the (originally only seven) prince-electors, the highest order of Reichsfürsten (comparable in rank with the French pairs), were prince-archbishops, each holding the title of Archchancellor (the only arch-office amongst them) for a part of the Empire; given the higher importance of an electorate, their principalities were known as Kurfürstentum ("electoral principality") rather than prince-archbishoprics:

Raised to an electorate in 1803, but simultaneously secularized; see Electorate of Salzburg. Since 1648, the archbishop has also borne the title Primas Germaniae, First [Bishop] of Germania. The powers of this title – non-jurisdictional – are limited to being the Pope's first correspondent in the German-speaking world, but used to include the right to preside over the Princes of the Holy Roman Empire.

Continued by Lutheran administrators after Reformation until 1645/1648, when it was continued as a secular and independent principality until its disestablishment in 1807. It became a part of the Kingdom of Hanover in 1815.

The suffragan-bishoprics of Gurk (established 1070), Chiemsee (1216), Seckau (1218), and Lavant (1225) sometimes used the Fürstbischof title, but never held any reichsfrei territory. The bishops of Vienna (established 1469) and Wiener Neustadt (1469–1785) didn't control any territory, nor did they claim a princely title.

Within this larger conflict, the continued dualism of the autonomous Riga prince-bishop and the Teutonic Knights led to a lengthy friction. Around 1245 the Papal legate William of Modena reached a compromise: though incorporated into the Order's State, the archdiocese and its suffragan bishoprics were acknowledged with their autonomous ecclesiastical territories by the Teutonic Knights. The bishops pursued the conferment of the princely title by the Holy Roman Emperor to stress their sovereignty. In the original Prussian lands of the Teutonic Order, Willam of Modena established the suffragan bishoprics of Culm, Pomesania, Samland and Warmia. From the late 13th century onwards, the appointed Warmia bishops were no longer members of the Teutonic Knights, a special status confirmed by the bestowal of the princely title by Emperor Charles IV in 1356.

The Bishops of Durham were also territorial prince-bishops, with the extraordinary secular rank of Earl palatine, for it was their duty not only to be head of the large diocese, but also to help protect the Kingdom against the Scottish threat from the north. The title survived the union of England and Scotland into the Kingdom of Great Britain in 1707 until 1836.

Apart from territories formerly within the Holy Roman Empire, no French diocese had a principality of political significance linked to its see.

However, a number of French bishops did hold a noble title, with a tiny territory usually about their seat; it was often a princely title, especially Count. Indeed, six of the original Pairies (the royal vassals awarded with the highest precedence at Court) were episcopal: the Archbishop of Reims and five other bishops (suffragans to Reims, except the Bishop of Langres); the three highest ones held a ducal title and the others a comital title.

From 1472 to 1967, the bishop of Coimbra held the comital title of Count of Arganil, being thus called "bishop-count" (Bispo-Conde, in Portuguese). The comital title is still held de jure, but since Portugal is a republic and nobility privileges are abolished, its use declined during the 20th century.

While one might expect that the Protestant Schism, Counter-Reformation and more modern regimes than the traditional feudal principality would have eradicated the prince-bishopric, they didn't quite.

Even when the true prince-(arch)bishoprics disappeared from the map of Europe as it was redrawn by Napoleon I Bonaparte (who caused the end of the Holy Roman Empire) and the Congress of Vienna after his defeat, the title found a new, titular use.

In the Habsburg dynasty's "new" empire, the Danubian Double Monarchy Austria-Hungary, reduced to the parts south of Prussia's (German) sphere of dominance that would become the (largely Protestant) German Empire, actual territorial power was no longer held by the bishops, but the status of Fürst(erz)bischof was maintained, and could be given a similar political role in the more modern, almost standardized Cisleithanian provincial level, the Kronland 'crown land', as ex officio members of its Landtag, the representative and legislative assembly, often with Virilstimme, while other bishops could collectively be represented as a 'prelates bench' (an elected Kurie).

The Emperors of Austria now bestowed the title upon bishops even without any feudal principality, but as a princely style and rank (as had been usual for centuries with secular noble titles of peerage ranks) awarded to episcopal sees, carrying the privilege of a seat in the estates, e.g., for the bishop of Laibach (as a consolation prize for the see's loss of metropolitan rank to Görz), the archbishop of Vienna (probably due to Vienna's rank as Imperial residence) and for the archbishop of Esztergom (here reflecting his longstanding rôle as the first magnate of Hungary).